Notice that in the previous query, each column name uses the standard naming convention of table-name.column-name. This can be cumbersome and prone to errors, especially with complex joins. A more convenient way is to define table aliases in the WHERE clause and invoke them throughout the query. The following example modifies the inner join in the previous example by employing table aliases. 

SELECT o.ordernum, o.custnum, c.name, o.orderdate, o.shipdate
FROM order o INNER JOIN customer c
ON o.custnum = c.custnum;